I searched for a thread I read recently on the topic and was unsuccessful. But here's how I do it. I water the plant first. Exposing roots to dry air isn't a good idea. I turn the pot over and let it slip out into my hands. I sit the whole root ball on a table and pluck at some of the roots to get them loosened up. If there are a lot of roots at the bottom of the rootball I either prune them away or just loosen them up, depending. After the plants are repotted you have to water them in. That's about it. I don't lose too many plants so it does work for me. Hope it works for you too.